A key requirement of a broad band telecommunications network is that of scheduling bandwidth allocation in response to user demand to ensure efficient operation of the network and to maximise the revenue earning traffic that may be carried. Typically, this task is performed by the use of a scheduling algorithms.
Many scheduling algorithms are known, based on fundamental Weighted Fair Queuing concept. However, the basic Weighted Fair Queuing algorithm that is commonly used suffers from a number of disadvantages including:                computational complexity is high,        it does not provide fairness when the output bandwidth fluctuates,        it requires length of packets to be known        it exhibits higher unfairness        it causes higher delay to low throughput applications.        
In an attempt to mitigate those disadvantages, some workers have employed Start Time Fair Queuing algorithm. This however, has the specific limitations that:                instantaneous nature of congestion is not accounted for and        inter-packet delay can grow very large.        